High-frequency compound switch module and communication terminal using it

ABSTRACT

A high-frequency compound switch module of this invention has a first communication system comprising a switch unit for switching connection of a signal from an antenna to one of a transmission circuit and a reception circuit of the first communication system based on a signal from a control terminal, a filter provided on a first reception circuit side, for filtering out a first reception signal, and a first phase shift line provided between the filter and the switch unit, and a second communication system comprising a second phase shift line provided between the switch unit and the first phase shift line, and a branching filter provided in series to the second phase shift line for branching a signal from the second phase shift line into a second transmission signal and a second reception signal. The switch module is capable of performing at least a receiving process of the first communication system while performing transmission/reception with the second communication system.

FIELD OF THE INVENTION

The present invention relates to a high-frequency compound switch moduleadaptable for use in a mobile communication device such as a handy phoneand the like. The invention also relates to a communication terminalusing the same.

BACKGROUND OF THE INVENTION

In recent years, communication devices like handy phones continue toadvance their functions toward multiband communications and combinationswith new systems to secure a number of channels and to cope withintroduction of new systems such as so-called third generation systemand the like due to an upsurge in the number of subscribers in theindividual mobile telephone systems. In addition, there is a growingdemand for miniaturization and reduction of insertion losses oncomponents used for the handy phones.

In GSM (i.e. Global System for Mobile Communications), which has comeinto widespread use from Europe to the world, there has been introduceda communication system using 900 MHz band and 1,800 MHz band, anddual-band communication terminals supporting this system are nowavailable in the market. FIG. 11 shows a circuit block diagram of anantenna front-end section of a dual-band handy phone adapted to acombination of GSM (transmission in a range of 880 to 915 MHz andreception in a range of 925 to 960 MHz) and DCS (i.e. Digital CellularSystem, for transmission in a range of 1,710 to 1,785 MHz and receptionin a range of 1,805 to 1,880 MHz).

In FIG. 11, the antenna front-end section comprises antenna terminal101, transmission terminals 102 and 103, reception terminals 104 and105, diplexer 106 for combining and branching GSM transmission/receptionsignals and DCS transmission/reception signals, switches 107 and 108 forselection between transmission and reception of GSM and DCS servicesrespectively, LPF's 109 and 110 for filtering off high harmoniccomponents of transmission signal of GSM and DCS services respectively,BPF's 111 and 112 having passbands corresponding to the respectivereceiving frequency bands of GSM and DCS services, and control terminals113 and 114 of the switches for selection of transmission and receptionof the GSM and DCS services respectively.

Surface acoustic wave (“SAW”) filter is an example of components used asBPF's 111 and 112. Switches 107 and 108 for selection betweentransmission and reception are SPDT (i.e. single-pole double-throw type)switches operable for selecting between transmission and reception inresponse to a voltage or the like impressed individually on controlterminals 113 and 114.

In addition, transmission terminals 102 and 103 are connected externallyto transmission circuits including transmission amplifiers 115 and 116,receiving side terminals 104 and 105 are connected externally toreception circuits including LNA's (i.e. low noise amplifiers) 117 and118 respectively, and antenna terminal 101 is connected to an antennaoutside, to constitute the communication device.

As W-CDMA (i.e. Wideband Code Division Multiple Access) employing CDMA(i.e. Code Division Multiple Access) method will be introduced in theforthcoming third generation, it is extremely important industrially tobring out compound terminals for both W-CDMA and GSM services in orderto use the existing GSM infrastructure effectively. In this case, it isnecessary for any such terminals to operate in a manner that it takesreception of GSM service while making communication with W-CDMAservices, and it also takes reception of W-CDMA service while being inreception with GSM at the same time, in order to ensure compatibilitywith the existing systems.

However, based as it is on the above-discussed structure of the priorart, it is not possible to adapt it for the compound function with theforthcoming third generation systems.

DISCLOSURE OF THE INVENTION

The present invention provides a high-frequency compound switch moduleadaptable to at least two different communication systems, and theswitch module includes a first communication system comprising a switchunit for switching connection of a signal from an antenna to one of atransmission circuit and a reception circuit of the first communicationsystem based on a signal from a control terminal, a filter provided onthe reception circuit side for filtering out a first reception signal,and a first phase shift line provided between the filter and the switchunit, and a second communication system comprising a second phase shiftline provided between the switch unit and the first phase shift line,and a branching filter provided in series to the second phase shift linefor branching a signal from the second phase shift line into a secondtransmission signal and a second reception signal. The high-frequencycompound switch module has a feature that simultaneously enables thesecond communication system to process the second transmission andreception signals when the switch unit of the first communication systemis turned to a first reception signal side.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a circuit block diagram according to a first exemplaryembodiment of the present invention;

FIG. 1B is another circuit block diagram according to the firstexemplary embodiment of the invention;

FIG. 1C is still another circuit block diagram according to the firstexemplary embodiment of the invention;

FIG. 2A is a circuit block diagram according to a second exemplaryembodiment of the invention;

FIG. 2B is another circuit block diagram according to the secondexemplary embodiment of the invention;

FIG. 2C is still another circuit block diagram according to the secondexemplary embodiment of the invention;

FIG. 3A is a circuit block diagram according to a third exemplaryembodiment of the invention;

FIG. 3B is another circuit block diagram according to the thirdexemplary embodiment of the invention;

FIG. 3C is still another circuit block diagram according to the thirdexemplary embodiment of the invention;

FIG. 4 is a circuit block diagram according to a fourth exemplaryembodiment of the invention;

FIG. 5 is a circuit block diagram according exemplary embodiment of theinvention;

FIG. 6 is a circuit block diagram according to a sixth exemplaryembodiment of the invention;

FIG. 7 represents block diagrams showing structural examples of phaseshift lines useful for this invention;

FIG. 8 is a perspective view of a high-frequency compound switch moduleaccording to another exemplary embodiment of this invention;

FIG. 9 represents schematic illustrations showing structure of ahigh-frequency compound switch module according to another exemplaryembodiment of this invention;

FIG. 10 represents schematic illustrations showing structure of anotherhigh-frequency compound switch module according to another exemplaryembodiments of this invention; and

FIG. 11 is a block diagram representing a conventional circuit.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Description is hereinafter provided individually of exemplaryembodiments of this invention with reference to the accompanyingdrawings.

First Exemplary Embodiment

Referring to the drawings, description is now given of the firstexemplary embodiment.

FIG. 1A is a circuit block diagram of a high-frequency compound switchmodule according to the first exemplary embodiment. In FIG. 1A, thehigh-frequency compound switch module comprises antenna terminal 1,transmission terminal 2 for a first system, reception terminal 3 for thefirst system, transmission terminal 4 for a second system, receptionterminal 5 for the second system, control terminal 6, SPDT switch 7,first phase shift line 8, second phase shift line 9, low pass filter(“LPF”) 10 for filtering out high harmonic components of a transmissionsignal in the first system, band pass filter 11 for passing a signal ofreceiving frequency band in the first system, and branching filter 12for branching and combining transmission and reception signals of thesecond system.

In FIG. 1A, band pass filter 11 comprises surface acoustic wave (“SAW”)filter, and branching filter 12 employs SAW filters 13 and 14 for bothtransmission side and reception side.

Third phase shift line 15 is used for impedance matching to achieve thefunction of branching and combining the transmission and receptionsignals of the second system. Transmission terminals 2 and 4 areconnected externally to transmission circuits including transmissionamplifiers 16 and 17, and receiving side terminals 3 and 5 are connectedexternally to reception circuits including LNA's (i.e. low noiseamplifiers) 18 and 19.

Antenna terminal 1 is connected externally to an antenna to constitute acommunication device.

SPDT switch 7 is controlled by a voltage applied to control terminal 6,to switch between transmission and reception modes in the first system,so as to make a connection of antenna terminal 1 to transmissionterminal 2 in the transmission mode, or the connection of antennaterminal 1 to reception terminal 3 in the reception mode. SPDT switch 7has first phase shift line 8 and SAW filter 11 connected to one sideleading to reception terminal 3.

In addition, phase shift line 9 and branching filter 12 for branchingand combining transmission and reception signals of the second systemare connected to a splice between SPDT switch 7 and phase shift line 8,and branching filter 12 is then connected to transmission terminal 4 andreception terminal 5 as their respective external terminals.

The first exemplary embodiment can be applied to a communication system,which uses TDMA (Time Division Multiple Access) as the first system, andCDMA or FDMA (Frequency Division Multiple Access) as the second system.

In consideration of frequency allocations for any communication system,a transmission frequency band and a reception frequency band are setrelatively close to each other in general, with a difference ofapproximately 5% between their center frequencies. In the communicationsystem of the first exemplary embodiment, however, separation offrequencies is quite large between different systems as compared to theabove, as individual systems are served in the widely spaced frequencybands.

Therefore, SAW filter 11 of the first communication system in thisexemplary embodiment has a passing characteristic with an attenuationband lying in a region of the transmission and reception frequencies ofthe second communication system. At these frequencies, SAW filter 11thus shows a small value in real part (i.e. resistive component) ofinput impedance, which can be plotted in a region near a circle of realpart=0 in the Smith chart, and a reflection coefficient close tomagnitude 1 in absolute value.

On the other hand, branching filter 12 also has a passing characteristicwith an attenuation band lying in a region of the transmission andreception frequencies of the first communication system, so that itshows a small value in real part (i.e. resistive component) of inputimpedance as measured from the side nearer to antenna terminal 1, whichcan be plotted in a region near the circle of real part=0 in the Smithchart, and a reflection coefficient close to magnitude 1 in absolutevalue (approx. 0.8 or greater).

The present invention is devised in light of the above respects, thatthe module is constructed by connecting first phase shift line 8 in amanner to provide a sufficiently large (open-circuit) impedance in thefrequencies of the second communication system when observed from pointA shown in FIG. 1A toward reception terminal 3 through first phase shiftline 8, and second phase shift line 9 in a manner to provide asufficiently large (open-circuit) impedance in the frequencies of thefirst communication system when observed from the same point A towardtransmission terminal 4 and reception terminal 5 through second phaseshift line 9, thereby making it operable in a combination of the twodifferent first and second communication systems.

In other words, adoption of the above structure makes it possible toreceive a pilot signal transmitted from a base station of the firstcommunication system and to control the communication deviceappropriately even when communication is being made with the secondcommunication system, since a desired control signal can be input tocontrol terminal 6 to control SPDT switch 7 in a manner to make aconnection between antenna terminal 1 and reception terminal 3simultaneously for the signal received in the first communication systemeven in the midst of communication with the second communication system.

The first exemplary embodiment can be applied to a compound terminalthat uses a combination of, for instance, GSM 900 (transmissionfrequency of the terminal in a range of 880 to 915 MHz and receivingfrequency in a range of 925 to 960 MHz), and W-CDMA (transmissionfrequency in a range of 1,920 to 1,980 MHz and receiving frequency in arange of 2,110 to 2,170 MHz).

Although what has been discussed in this first exemplary embodiment isan example equipped with phase shift lines 8 and 9, they may be replacedwith diplexer 40 as shown in FIG. 1B. Use of diplexer 40 can providemore stable performance because it is not dependent on input impedancecharacteristics of SAW filter 11 and branching filter 12.

Furthermore, as a modified structure of the first exemplary embodiment,diplexer 40 may be connected to antenna terminal 1, as shown in FIG. 1C.This structure can also provide more stable performance since operationof diplexer 40 is not dependent on the input impedance characteristicsof SAW filter 11 and branching filter 12. In addition, this structurecan reduce a transmission loss of the second communication systembecause a signal passage of the second communication system does notinclude SPDT switch 7, in contrast to those of FIG. 1A and FIG. 1B.Because SPDT switch 7 has a transmission loss of approximately 0.5 dB,the loss can be reduced by a magnitude of this amount.

Moreover, the module may be so constructed as not to include SAW filter11 and branching filter 12 in the circuit structures shown in FIG. 1Band FIG. 1C.

Second Exemplary Embodiment

Referring now to FIG. 2, description is provided of the second exemplaryembodiment of this invention.

FIG. 2A is a circuit block diagram of a high-frequency compound switchmodule according to the second exemplary embodiment. Description will beskipped of any parts of the structure in FIG. 2A that are analogous tothe first exemplary embodiment.

The high-frequency compound switch module comprises transmissionterminal 20 in a third communication system, reception terminal 21 inthe third communication system, SP4T (single-pole quadruple-throw type)switch 22 for switching connection of antenna terminal 1 to individualbranches by means of control terminal 6, low pass filter (“LPF”) 23 forfiltering out higher harmonic components of a transmission signal in thethird system, and band pass filter 24 for passing a signal of receivingfrequency band in the third system. Transmission terminal 20 andreception terminal 21 are connected externally to transmission circuitsincluding transmission amplifier 25 and reception circuits including LNA26 respectively in the like manner as the first exemplary embodiment, toconstitute a communication device adoptable for three communicationsystems.

In FIG. 2A, band pass filters 11 and 24 comprise surface acoustic wave(“SAW”) filters.

Branching filter 12 employs SAW filters 13 and 14 for both of atransmission side and a reception side, and it uses third phase shiftline 15 for impedance matching to achieve the function of branching andcombining transmission and reception signals of a second communicationsystem.

SP4T switch 22 is controlled by a voltage applied to control terminal 6,to switch the connection of antenna terminal 1 to any of transmissionterminal 2, transmission terminal 20, reception terminal 3 and receptionterminal 21 by making selection of any of transmission and receptionmodes in the first communication system, and transmission and receptionmodes in the third communication system.

First phase shift line 8 and SAW filter 11 are connected between SP4Tswitch 22 and reception terminal 3.

Second phase shift line 9 is connected between SP4T switch 22 and firstphase shift line 8, and: this second phase shift line 9 is in seriesconnection to branching filter 12 for branching and combiningtransmission and reception signals of the second communication system,which is then connected to transmission terminal 4 and receptionterminal 5 as their respective external terminals.

The second exemplary embodiment can be applied to a system, which usesTDMA method as the first and the third communication systems, and CDMAor FDMA as the second communication system.

In consideration of frequency allocations for any of the communicationsystems, a transmission frequency band and a reception frequency bandare set relatively close to each other in general, with a difference ofapproximately 5% between their center frequencies. In the communicationsystem of the second exemplary embodiment, however, separation offrequencies is quite large between different systems as compared to theabove, since individual systems are served in the widely spacedfrequency bands.

Therefore, SAW filter 11 of the first communication system in the secondexemplary embodiment has a passing characteristic with an attenuationband lying in a region of the transmission and reception frequencies ofthe second communication system. It thus shows a small value in realpart (i.e. resistive component) of input impedance at these frequencies,which can be plotted in a region near a circle of real part=0 in theSmith chart, and a reflection coefficient close to magnitude 1 inabsolute value. On the other hand, branching filter 12 also has apassing characteristic with an attenuation band lying in a region of thetransmission and reception frequencies of the first communicationsystem, so that it shows a small value in real part (i.e. resistivecomponent) of input impedance as measured from the side nearer toantenna terminal 1, which can be plotted in a region near the circle ofreal part=0 in the Smith chart, and a reflection coefficient close tomagnitude 1 in absolute value (approx. 0.8 or greater).

The present invention is devised in light of the above respects, thatthe module is constructed by connecting first phase shift line 8 in amanner to provide a sufficiently large (open-circuit) impedance in thefrequencies of the second communication system when observed from pointA shown in FIG. 2A toward reception terminal 3 through first phase shiftline 8, and second phase shift line 9 in a manner to provide asufficiently large (open-circuit) impedance in the frequencies of thefirst communication system when observed from the same point A towardtransmission terminal 4 and reception terminal 5 through second phaseshift line 9, thereby making it operable in a combination of the twodifferent first and second communication systems.

In other words, adoption of the above structure makes it possible toreceive a pilot signal transmitted from a base station of the firstcommunication system and to control the communication deviceappropriately even when communication is being made with the secondcommunication system, since a required control signal can be input tocontrol terminal 6 to control SP4T switch 22 in a manner to make aconnection between antenna terminal 1 and reception terminal 3simultaneously for the signal received in the first communication systemeven in the midst of communication with the second communication system.

The second exemplary embodiment can be applied to a compound terminalthat uses a combination of, for instance, GSM 900 (transmissionfrequency of the terminal in a range of 880 to 915 MHz, and receivingfrequency in a range of 925 to 960 MHz) as the first communicationsystem, W-CDMA (transmission frequency in a range of 1,920 to 1,980 MHz,and receiving frequency in a range of 2,110 to 2,170 MHz) as the secondcommunication system, and DCS (transmission frequency in a range of1,710 to 1,785 MHz and receiving frequency in a range of 1,805 to 1,880MHz) as the third communication system. In the communication system ofthis application, although the communication frequencies arecomparatively close to each other especially between the secondcommunication system and the third communication system, use of SP4Tswitch 22 can achieve separation of the signals easily withoutincreasing the transmission loss.

Although what has been discussed in the second exemplary embodiment isan example equipped with phase shift lines 8 and 9, they may be replacedwith diplexer 40 as shown in FIG. 2B. Use of diplexer 40 can providestable performance because it is not dependent on input impedancecharacteristics of SAW filter 11 and branching filter 12.

In addition, as a modified structure of the second exemplary embodiment,the module may be composed with SP3T switch 34 in place of SP4T switch22, with the addition of diplexer 40 connected to SP3T switch 34 asshown in FIG. 2C. This structure can provide more stable performancesince operation of diplexer 40 is not dependent on the input impedancecharacteristics of SAW filter 11 and branching filter 12. This structurealso allows use of more simplified switch as compared to the structuresof FIG. 2A and FIG. 2B. In other words, the SP4T switch can be replacedwith the SP3T switch to simplify the switching circuit. When the SP3Tswitch is composed of GaAs-IC, for instance, it can reduce a size of thechip, lower the transmission loss, and reduced the cost while realizingdownsizing of the module, since it decreases a number of ports of the ICto be tested before the shipment.

Moreover, this module may be so constructed as not to include SAW filter11 and branching filter 12 in the circuit structures shown in FIG. 2Band FIG. 2C.

Third Exemplary Embodiment

The third exemplary embodiment is described hereinafter with referenceto the drawings.

FIG. 3A is a circuit block diagram of a high-frequency compound switchmodule according to the third exemplary embodiment.

Description will be skipped of any parts of the structure in FIG. 3Athat are analogous to the first and the second exemplary embodiments.

The high-frequency compound switch module comprises transmissionterminal 20 common to a third and a fourth communication systems, LPF 23for filtering out higher harmonic components contained in a third and afourth transmission signals, reception terminal 27 in the fourthcommunication system, SP5T (i.e. single-pole quintuple-throw type)switch 28 for switching connection of antenna terminal 1 to individualbranches by means of control terminal 6, and band pass filter 29 forpassing a signal of receiving frequency band of the fourth communicationsystem. Transmission terminal 20 and reception terminal 27 are connectedexternally to transmission amplifier 25 and LNA 30 respectively in thelike manner as the second exemplary embodiment, to constitute acommunication device adoptable for the four communication systems.

When surface acoustic wave (“SAW”) filters are used for band passfilters 11, 24 and 29 in FIG. 3A, branching filter 12 is also providedwith SAW filters 13 and 14 for both the transmission side and thereception side, in addition to third phase shift line 15 for impedancematching, to accomplish the function of branching and combiningtransmission and reception signals of the second communication system.

SP5T switch 28 is controlled by a voltage applied to control terminal 6to switch the connection of antenna terminal 1 to any of transmissionterminal 2, transmission terminal 20, reception terminal 3, receptionterminal 21 and reception terminal 27, so as to make a selection of anyof transmission and reception modes in the first communication system,transmission and reception modes in the third communication system, andtransmission and reception modes in the fourth communication system.

First phase shift line 8 and SAW filter 11 are connected between SP5Tswitch 28 and reception terminal 3. Second phase shift line 9 isconnected between SP5T switch. 28 and reception terminal 5. Second phaseshift line 9 is connected in series to branching filter 12 for branchingand combining transmission and reception signals of the secondcommunication system, which is then connected to transmission terminal 4and reception terminal 5 as their respective external terminals.

The third exemplary embodiment can be applied to a system, which usesTDMA method as the first, third, and fourth communication systems, andCDMA or FDMA as the second communication system.

In consideration of frequency allocations for any of the communicationsystems, a transmission frequency band and a reception frequency bandare set relatively close to each other in general, with a difference ofapproximately 5% between their center frequencies. In the communicationsystem discussed in the third exemplary embodiment, however, separationof frequencies is quite large between different systems as compared tothe above, since individual systems are served in the widely spacedfrequency bands.

Therefore, SAW filter 11 of the first communication system in the thirdexemplary embodiment has a passing characteristic with an attenuationband lying in a region of the transmission and reception frequencies ofthe second communication system. It thus shows a small value in realpart (i.e. resistive component) of input impedance at these frequencies,which can be plotted in a region near a circle of real part=0 in theSmith chart, and a reflection coefficient close to magnitude 1 inabsolute value.

On the other hand, branching filter 12 also has a passing characteristicwith an attenuation band lying in a region of the transmission andreception frequencies of the first communication system, so that itshows a small value in real part (i.e. resistive component) of inputimpedance as measured from the side nearer to antenna terminal 1, whichcan be plotted in a region near the circle of real part=0 in the. Smithchart, and a reflection coefficient close to magnitude 1 in absolutevalue (approx. 0.8 or greater).

The present invention is devised in light of the above respects, thatthe module is constructed by connecting first phase shift line 8 in amanner to provide a sufficiently large (open-circuit) impedance in thefrequencies of the second communication system when observed from pointA shown in FIG. 3A toward reception terminal 3 through first phase shiftline 8, and second phase shift line 9 in a manner to provide asufficiently large (open-circuit) impedance in the frequencies of thefirst communication system when observed from the same point A towardtransmission terminal 4 and reception terminal 5 through second phaseshift line 9, thereby making it operable in the combination of the twodifferent first and second communication systems.

Adoption of the above structure makes it possible to receive a pilotsignal transmitted from a base station of the first communication systemand to control the communication device appropriately even whencommunication is being made with the second communication system, sincea desired control signal can be input to control terminal 6 to controlSP5T switch 28 in a manner to make a connection between antenna terminal1 and reception terminal 3 simultaneously for the signal received in thefirst communication system even in the midst of communication with thesecond communication system.

The third exemplary embodiment can be applied to a compound terminalthat uses a combination of, for instance, GSM 900 (transmissionfrequency of the terminal in a range of 880 to 915 MHz, and receivingfrequency in a range of 925 to 960 MHz) as the first communicationsystem, W-CDMA (transmission frequency in a range of 1,920 to 1,980 MHz,and receiving frequency in a range of 2,110 to 2,170 MHz) as the secondcommunication system, DCS (transmission frequency in a range of 1,710 to1,785 MHz and receiving frequency in a range of 1,805 to 1,880 MHz) asthe third communication system, and GSM service in the United Stateswhich uses the PCS frequency band (transmission frequency in a range of1,850 to 1,910 MHz and receiving frequency in a range of 1,930 to 1,990MHz) as the fourth communication system. In the communication system ofthe above application, although the communication frequencies arecomparatively close to one another especially among the second, thethird and the fourth communication systems, use of SP5T switch 28 canachieve separation of the signals easily without increasing thetransmission loss.

Although what has been discussed in the third exemplary embodiment is anexample having phase shift lines 8 and 9, they may be replaced withdiplexer 40 as shown in FIG. 3B. Use of diplexer 40 can provide stableperformance because it is not dependent upon input impedancecharacteristics of SAW filter 11 and branching filter 12.

In addition, as a modified structure of the third exemplary embodiment,the module may be composed with SP4T switch 22 in place of SP5T switch28, with the addition of diplexer 40 connected to SP4T switch 22 asshown in FIG. 3C. This structure can provide more stable performancesince operation of diplexer 40 is not dependent on the input impedancecharacteristics of SAW filter 11 and branching filter 12. This structurealso allows use of rather simplified switch as compared to thestructures of FIG. 3A and FIG. 3B. In other words, the SP5T switch canbe replaced with the SP4T switch to simplify the switching circuit. Whenthe switch is composed of GaAs-IC, for instance, it can reduce a size ofthe chip, lower the transmission loss, and reduced the cost whilerealizing downsizing of the module, since it decreases a number of portsof the IC to be tested before the shipment.

Moreover, this module may be so constructed as not to include SAW filter11 and branching filter 12 in the circuit structures shown in FIG. 3Band FIG. 3C.

Fourth Exemplary Embodiment

Description is provided hereinafter of the fourth exemplary embodimentwith reference to FIG. 4.

FIG. 4 is a circuit block diagram of a high-frequency compound switchmodule according to the fourth exemplary embodiment.

Description will be skipped of any parts of the structure in FIG. 4 thatare analogous to the first through the third exemplary embodiments.

SPST (single-pole single-throw type) switch 31 is connected to antennaterminal 1 in parallel with SP4T switch 22 to turn on/off a secondcommunication system.

The fourth exemplary embodiment represents a high-frequency compoundswitch module adaptable to three communication systems similar to thatof the second exemplary embodiment.

In FIG. 4, band pass filters 11 and 24 comprise surface acoustic wave(“SAW”) filters, and branching filter 12 employs SAW filters 13 and 14for both of a transmission side and a reception side, and third phaseshift line 15 for impedance matching, to achieve the function ofbranching and combining transmission and reception signals of the secondcommunication system.

SP4T switch 22 and SPST switch 31 are controlled individually by avoltage applied to control terminal 6, for selection betweentransmission and reception modes in the first communication system,between transmission and reception modes in the third communicationsystem, and switching on/off of a connection in the second communicationsystem.

SP4T switch 22 operates in a manner to make connection of antennaterminal 1 to any of transmission terminal 2, transmission terminal 20,reception terminal 3 and reception terminal 21. SP4T switch 22 has firstphase shift line 8 and SAW filter 11 connected to one side leading toreception terminal 3.

SPST switch 31 has branching filter 12 connected at one side forbranching and combining transmission and reception signals of the secondcommunication system, which is then connected to transmission terminal 4and reception terminal 5 as their respective external terminals.

Thus, the fourth exemplary embodiment can be applied to a communicationsystem, which uses TDMA method as the first and third communicationsystems, and CDMA or FDMA as the second communication system.

In consideration of frequency allocations for any of the communicationsystems, a transmission frequency band and a reception frequency bandare set relatively close to each other in general, with a difference ofapproximately 5% between their center frequencies. In the communicationsystem discussed in the fourth exemplary embodiment, however, separationof frequencies is quite large between different systems as compared tothe above, since individual systems are served in the widely spacedfrequency bands.

Therefore, SAW filter 11 of the first communication system in the fourthexemplary embodiment has a passing characteristic with an attenuationband lying in a region of the transmission and reception frequencies ofthe second communication system. It thus shows a small value in realpart (i.e. resistive component) of input impedance at these frequencies,which can be plotted in a region near a circle of real part=0 in theSmith chart, and a reflection coefficient close to magnitude 1 inabsolute value. On the other hand, branching filter 12 also has apassing characteristic with an attenuation band lying in a region of thetransmission and reception frequencies of the first communicationsystem, so that it shows a small value in real part (i.e. resistivecomponent) of input impedance as measured from the side nearer toantenna terminal 1, which can be plotted in a region near the circle ofreal part=0 in the Smith chart, and a reflection coefficient close tomagnitude 1 in absolute value (approx. 0.8 or greater).

The present invention is devised in light of the above respects, thatthe module is constructed by connecting first phase shift line 8 in amanner to provide a sufficiently large (open-circuit) impedance in thefrequencies of the second communication system when observed from pointA shown in FIG. 4 toward reception terminal 3 through SP4T switch 22 andfirst phase shift line 8, and second phase shift line 9 in a manner toprovide a sufficiently large (open-circuit) impedance in the frequenciesof the first communication system when observed from the same point Atoward transmission terminal 4 and reception terminal 5 through SPSTswitch 31 and second phase shift line 9, thereby making it operable inthe combination of the two different first and second communicationsystems.

In other words, adoption of the above structure makes it possible toreceive a pilot signal transmitted from a base station of the firstcommunication system and to control the communication deviceappropriately even when communication is being made with the secondcommunication system, since a required control signal can be input tocontrol terminal 6 to control SP4T switch 22 and SPST switch 31 in amanner to make a connection between antenna terminal 1 and receptionterminal 3 simultaneously for the signal received in the firstcommunication system even in the midst of communication with the secondcommunication system.

The fourth exemplary embodiment can be applied to a compound terminalthat uses a combination of, for instance, GSM 900 (transmissionfrequency of the terminal in a range of 880 to 915 MHz, and receivingfrequency in a range of 925 to 960 MHz) as the first communicationsystem, W-CDMA (transmission frequency in a range of 1,920 to 1,980 MHz,and receiving frequency in a range of 2,110 to 2,170 MHz) as the secondcommunication system, and DCS (transmission frequency in a range of1,710 to 1,785 MHz and receiving frequency in a range of 1,805 to 1,880MHz) as the third communication system. In the communication system ofthis application, although the communication frequencies arecomparatively close to each other especially between the secondcommunication system and the third communication system, use of SPSTswitch 31 can achieve separation of the signals easily withoutincreasing the transmission loss.

Fifth Exemplary Embodiment

Description is provided hereinafter of the fifth exemplary embodimentwith reference to FIG. 5.

FIG. 5 is a circuit block diagram of a high-frequency compound switchmodule according to the fifth exemplary embodiment.

Description will be skipped of any parts of the structure in FIG. 5 thatare analogous to the first through the fourth exemplary embodiments.

This exemplary embodiment composes a communication device adaptable tofour communication systems in all, as similar to that of the thirdexemplary embodiment.

In FIG. 5, band pass filters 11, 24 and 29 comprise surface acousticwave (“SAW”) filters.

Branching filter 12 employs SAW filters 13 and 14 for both of atransmission side and a reception side, and third phase shift line 15for impedance matching, to achieve the function of branching andcombining transmission and reception signals of the second communicationsystem.

SP5T switch 28 and SPST switch 31 are controlled by a voltage applied tocontrol terminal 6, for selection between transmission and receptionmodes in the first communication system, between transmission andreception modes in the third communication system, between transmissionand reception modes in the fourth communication system, and switchingon/off of a connection in the second communication system. SP5T switch28 operates in a manner to make connection of antenna terminal 1 to anyof transmission terminal 2, transmission terminal 20, reception terminal3, reception terminal 21 and reception terminal 27.

First phase shift line 8 and SAW filter 11 are connected between SP5Tswitch 28 and reception terminal 3. Second phase shift line 9 andbranching filter 12 for branching and combining transmission andreception signals of the second communication system are connected toSPST switch. 31, and branching filter 12 is lead to transmissionterminal 4 and reception terminal 5 as their respective externalterminals.

In the fifth exemplary embodiment, the module can be applied to acommunication system, which uses TDMA method as the first, the third andthe fourth communication systems, and CDMA or, FDMA as the secondcommunication system.

In consideration of frequency allocations for any of the communicationsystems, a transmission frequency band and a reception frequency bandare set relatively close to each other in general, with a difference ofapproximately 5% between their center frequencies. In the communicationsystem discussed in the fifth exemplary embodiment, however, separationof frequencies is quite large between different systems as compared tothe above, since individual systems are served in the widely spacedfrequency bands.

Therefore, SAW filter 11 of the first communication system in the fifthexemplary embodiment has a passing characteristic with an attenuationband lying in a region of the transmission and reception frequencies ofthe second communication system. It thus shows a small value in realpart (i.e. resistive component) of input impedance at these frequencies,which can be plotted in a region near a circle of real part=0 in theSmith chart, and a reflection coefficient close to magnitude 1 inabsolute value.

On the other hand, branching filter 12 also has a passing characteristicwith an attenuation band lying in a region of the transmission andreception frequencies of the first communication system, so that itshows a small value in real part (i.e. resistive component) of inputimpedance as measured from the side nearer to antenna terminal 1, whichcan be plotted in a region near the circle of real part=0 in the Smithchart, and a reflection coefficient close to magnitude 1 in absolutevalue (approx. 0.8 or greater).

The present invention is devised in light of the above respects, thatthe module is constructed by connecting first phase shift line 8 in amanner to provide a sufficiently large (open-circuit) impedance in thefrequencies of the second communication system when observed from pointA shown in FIG. 5 toward reception terminal 3 through SP5T switch 28 andfirst phase shift line 8, and second phase shift line 9 in a manner toprovide a sufficiently large (open-circuit) impedance in the frequenciesof the first communication system when observed from the same point Atoward transmission terminal 4 and reception terminal 5 through SPSTswitch 31 and second phase shift line 9, thereby making it operable inthe combination of the two different first and second communicationsystems.

In other words, adoption of the above structure makes it possible toreceive a pilot signal transmitted from a base station of the firstcommunication system and to control the communication deviceappropriately even when communication is being made with the secondcommunication system, since a required control signal can be input tocontrol terminal 6 to control SP5T switch 28 and SPST switch 31 in amanner to make a connection between antenna terminal 1 and receptionterminal 3 simultaneously for the signal received in the firstcommunication system even in the midst of communication with the secondcommunication system.

The fifth exemplary embodiment can be applied to a compound terminalthat uses a combination of, for instance, GSM 900 (transmissionfrequency of the terminal in a range of 880 to 915 MHz, and receivingfrequency in a range of 925 to 960 MHz) as the first communicationsystem, W-CDMA (transmission frequency in a range of 1,920 to 1,980 MHz,and receiving frequency in a range of 2,110 to 2,170 MHz) as the secondcommunication system, DCS (transmission frequency in a range of 1,710 to1,785 MHz and receiving frequency in a range of 1,805 to 1,880 MHz) asthe third communication system, and GSM service in the United Stateswhich uses the PCS frequency band (transmission frequency in a range of1,850 to 1,910 MHz and receiving frequency in a range of 1,930 to 1,990MHz) as the fourth communication system. In the communication system ofthe above application, although the communication frequencies arecomparatively close to one another especially among the second, thethird and the fourth communication systems, use of SPST switch 31 canachieve separation of the signals easily without increasing thetransmission loss.

Sixth Exemplary Embodiment

Description is provided hereinafter of the sixth exemplary embodimentwith reference to FIG. 6.

FIG. 6 is a circuit block diagram of a high-frequency compound switchmodule according to the sixth exemplary embodiment.

Description will be skipped of any parts of the structure in FIG. 6 thatare analogous to the first through the fifth exemplary embodiments.

The high-frequency compound switch module comprises diplexer 32connected to antenna terminal 1 for branching and combining signals of afirst communication system as well as signals of a second and thirdcommunication system, SPDT switch 33 for switching between transmissionand reception modes of the first communication system, and SP3T(single-pole triple-throw type) switch 34 for switching betweentransmission and reception modes of the third communication system andalso for turning on/off the second communication system. This sixthexemplary embodiment constitutes a communication device adoptable forthree communication systems.

In FIG. 6, band pass filters 11 and 24 comprise surface acoustic wave(“SAW”) filters, and branching filter 12 employs SAW filters 13 and 14for both of a transmission side and a reception side. It shows anexample which uses third phase shift line 15 for impedance matching toachieve the function of branching and combining the transmission andreception signals of the second communication system.

SPDT switch 33 and SP3T switch 34 are controlled individually by avoltage or the like applied to control terminal 6, for a selectionbetween transmission and reception modes in the first communicationsystem, and between transmission and reception modes in the thirdcommunication system, in a manner to make connection of antenna terminal1 to any of transmission terminal 2, transmission terminal 20, receptionterminal 3 and reception terminal 21, after the signals are eitherbranched or combined by branching filter 12.

SPDT switch 33 has first phase shift line 8 and SAW filter 11 connectedto one side leading to reception terminal 3, and SP3T switch 34 hasbranching filter 12 for branching and combining transmission andreception signals of the second communication system connected to one ofconnection terminals. Branching filter 12 is then connected totransmission terminal 4 and reception terminal 5 as the respectiveexternal terminals.

Thus, the sixth exemplary embodiment can be applied to a communicationsystem, which uses TDMA method as the first and third communicationsystems, and CDMA or FDMA as the second communication system.

In consideration of frequency allocations for any of the communicationsystems, a transmission frequency band and a reception frequency bandare set relatively close to each other in general, with a difference ofapproximately 5% between their center frequencies. In the communicationsystem discussed in this sixth exemplary embodiment, however, separationof frequencies is quite large between different systems as compared tothe above, since individual systems are served in the widely spacedfrequency bands.

Therefore, SAW filter 11 of the first communication system in the sixthexemplary embodiment has a passing characteristic with an attenuationband lying in a region of the transmission and reception frequencies ofthe second communication system. It thus shows a small value in realpart (i.e. resistive component) of input impedance at these frequencies,which can be plotted in a region near a circle of real part=0 in theSmith chart, and a reflection coefficient close to magnitude 1 inabsolute value.

On the other hand, branching filter 12 also has a passing characteristicwith an attenuation band lying in a region of the transmission andreception frequencies of the first communication system, so that itshows a small value in real part (i.e. resistive component) of inputimpedance as measured from the side nearer to antenna terminal 1, whichcan be plotted in a region near the circle of real part=0 in the Smithchart, and a reflection coefficient close to magnitude 1 in absolutevalue (approx. 0.8 or greater).

The present invention is devised in light of the above respects, thatthe module is constructed by connecting first phase shift line 8 in amanner to provide a sufficiently large (open-circuit) impedance in thefrequencies of the second communication system when observed fromantenna terminal 1 toward reception terminal 3 through first phase shiftline 8, and second phase shift line 9 in a manner to provide asufficiently large (open-circuit) impedance in the frequencies of thefirst communication system when observed from antenna terminal 1 towardtransmission terminal 4 and reception terminal 5 through diplexer 32,SP3T switch 34 and second phase shift line 9, under the condition thatSPDT switch 33 is set to reception terminal 3 side and SP3T switch 34 isset to transmission terminal 4 and reception terminal 5 side of thesecond communication system in FIG. 6, thereby making it operable in thecombination of the two different first and second communication systems.

In other words, adoption of the above structure makes it possible toreceive a pilot signal transmitted from a base station of the firstcommunication system and to control the communication deviceappropriately even when communication is being made with the secondcommunication system, since a required control signal can be input tocontrol terminal 6 to control SPDT switch 33 and SP3T switch 34 in amanner to make a connection from antenna terminal 1 to receptionterminal 3 simultaneously for the signal received in the firstcommunication system even in the midst of communication with the secondcommunication system.

The sixth exemplary embodiment can be applied to a compound terminalthat uses a combination of, for instance, GSM 900 (transmissionfrequency of the terminal in a range of 880 to 915 MHz, and receivingfrequency in a range of 925 to 960 MHz) as the first communicationsystem, W-CDMA (transmission frequency in a range of 1,920 to 1,980 MHz,and receiving frequency in a range of 2,110 to 2,170 MHz) as the secondcommunication system, and DCS (transmission frequency in a range of1,710 to 1,785 MHz, and receiving frequency in a range of 1,805 to 1,880MHz) as the third communication system. In the communication system ofthis application, although the communication frequencies arecomparatively close to each other especially between the secondcommunication system and the third communication system, use of SP3Tswitch 34 can achieve separation of the signals easily withoutincreasing the transmission loss.

In the above discussed first through sixth exemplary embodiments, theSPDT, SP3T, SP4T and SP5T type switches may be composed of FET switchesmade by GaAs process and the like and PIN diode switches.

In addition, the BPF's connected to the reception terminals need not belimited only to the SAW filters as discussed above, but other types ofBPF's such as those made of dielectric resonator can also provide thelike advantage.

Moreover, although the branching filter in the second communicationsystem was described above as a structure having SAW filters, it may becomposed of a combination of one filter using a multilayer structure ofdielectric material for any of transmission and reception filters and anSAW filter for the other one, a kind of branching filter composed of amultilayer structure of dielectric material for both the transmissionand reception filters, another kind of branching filter composed offilters using coaxial resonator, and the like.

Furthermore, although the structures described in the above firstthrough sixth exemplary embodiments are provided with the low passfilters, they need not be included in the structure of this invention ifa circuit for filtering out high harmonic spurious components isprovided originally in the transmission circuit.

The first to the third phase shift lines shown above in the firstthrough the sixth exemplary embodiments can be configured of any ofstrip lines, micro-strip lines, coplanar lines, and the similar type oftransmission lines. Besides, the phase shift lines can also beconfigured of a π-type lumped constant circuit as shown in FIG. 7.

In any of the circuit structures described in the first through thesixth exemplary embodiments, the switches may be configured ofmonolithic IC, the filters may be composed using SAW filters, and mostof the remaining circuits may be formed using an electrode patternwithin a multilayer structure of dielectric material, as shown in FIG. 8and FIG. 9, wherein SAW filter 36, switch IC 37 and chip component 38are mounted on multilayer substrate 35 having input/output electrodesformed of side electrodes 39 or grid alley electrodes, thereby realizingthe high-frequency compound switch module extremely compact.

Adoption of the above structure can provide the high-frequency compoundswitch module, which is easy to manufacture, very compact and highperformance, since it uses the branching filter comprised of small SAWfilters having a low loss in the passing band and a high attenuationover the frequencies outside the passing band, and the multilayer filterhaving an affinity to the peripheral circuits.

In addition, the module may be composed with terminals arranged as shownin FIG. 10, wherein antenna (ANT) terminal is located on an uppersurface, and transmission side (GSM, DCS, W-CDMA-Tx) terminals andreception side (GSM, DCS, W-CDMA-Rx) terminals are centralizedseparately on the left to lower side area, and on the right to upperside area with respect to the antenna terminal, as viewed from top ofthe module. Accordingly, transmission circuits and reception circuitscan be disposed to the left side and the right side respectively in thiscase, when they are connected to the module. Since an arrangement suchas this example can avoid likelihood of performance degradation due tointeraction between the transmission circuits and the reception circuitsconstructed on a motherboard (not shown), it provides the wirelessterminal with superior performance.

It is important that switch IC 37 comprising the module has a proper pinlayout in order to achieve the advantage discussed above. This isevident from the fact that connections can be made very easily amongterminals of switch IC 37, circuits such as LPF's composed in multilayersubstrate 35, and SAW filters 36 a and 36 b, when switch IC 37 has thepin layout as shown in FIG. 10, in which transmission side ports arelocated around side 37 a, an antenna port at side 37 b, reception sideports around side 37 c, and control terminal ports around side 37 d.

Thus, it has been made clear that pin layout of switch IC 37 is of greatimportance to the module shown in FIG. 10, which does not exhibitdegradation in performance, is compact in size, and contributes toreliable operation of the transmission and reception circuits on themotherboard.

Moreover, it is extremely desirable for the module to have an electrodepattern as shown in FIG. 10 in order to further enhance the performance.That is, it is the first essential that all electrodes carryinghigh-frequency signals shall be made smaller in size as compared toelectrodes of the other purposes. The reason of this is to preventinfluence of stray capacity. As the second essential, all electrodeslocated in the corners are to be enlarged as much as the space permits.This is for an improvement of physical strength of the module aftermounted. The third essential is to dispose additional number of dummyelectrodes for the same purpose. The dummy electrodes can decentralize astress, to improve the physical strength.

In view of the above, the present invention is to provide the electrodestructure and the terminal arrangement shown in FIG. 10. In other words,electrode 41 b located in the corner is formed larger in size than theterminals used for carrying the high-frequency signals ,by using it asan electrode for GND, or VDD (i.e. power supply for switch IC 37), orany of Ctrl-1 through Ctrl-3 (i.e. control terminal of switch IC 37).There are also dummy electrodes (which may be connected to groundingGND) provided additionally in a center space.

These electrodes may be used as LGA electrodes to make this structurecontributable to even further improvement for ease of mounting andreliability in strength of the terminals. Because of the abovestructure, provided here is the device which is extremely superior inmechanical reliability and high-frequency characteristics.

In addition, this device may be covered with a metal cap (not shown) orcoated with resin or the like material (not shown) to form a smooth topsurface, thereby improving convenience of use when handled by a mountingmachine equipped with suction device.

The invention disclosed here is the high-frequency compound switchmodule featuring the structure comprising SAW filters that use bulk wavefor both filters in the transmission and the reception lines.

The above structure can provide the high-frequency compound switchmodule of high performance with even smaller size because it employs thebranching filter comprising the small SAW filters using bulk wave, whichhave low loss in the passing band and high magnitude of attenuation overthe, outside frequencies.

Moreover, this invention covers the high-frequency compound switchmodule featuring the structure comprising the first and second phaseshift lines which include any of π-type or T-type network having aline-to-ground capacitor and a series inductor, and π-type or T-typenetwork having a line-to-ground inductor and a series capacitor.

The above structure can realizes the phase shift lines of low insertionlosses with small deviation, and thereby it provides the high-frequencycompound switch module, which is easy to manufacture, small in size andhigh performance.

Furthermore, this invention also covers the high-frequency compoundswitch module featuring the structure of circuit comprising any of anelectrode pattern formed above a grounding pattern with a spacing ofdielectric material and another electrode pattern formed next to agrounding pattern with a spacing of dielectric material therebetween.

The above structure can realizes the phase shift lines of low insertionlosses with small deviation, and thereby it provides the high-frequencycompound switch module, which is easy to manufacture, small in size andhigh performance.

This invention also covers the high-frequency compound switch modulefeaturing the structure wherein at least the first and the second phaseshift lines in the circuit are formed with an electrode pattern insidethe multilayer structure of dielectric material.

The above structure makes possible to use LTCC (i.e. low temperatureco-fired ceramics) as the dielectric base material in combination withthe electrode pattern of silver or copper, to compose the circuit of lowloss in the high-frequency bands. Furthermore, since the circuit can becomposed three-dimensionally into the multilayer substrate, thehigh-frequency compound switch module can be made small in size and highperformance.

This invention also covers the high-frequency compound switch modulefeaturing the structure wherein the switch unit and the filters aremounted on the multilayer substrate.

The above structure comprises the major circuit formed inside themultilayer substrate, and that the filters and the switch unit notfeasible to build into the multilayer substrate are mounted on themultilayer substrate. Since this structure makes use of the multilayersubstrate as a substrate to complete electrical connections of thefilters, switch unit and the other peripheral circuits, it can providethe high-frequency compound switch module easy to manufacture, small insize and high performance.

Moreover, this invention is the high-frequency compound switch moduleadaptable for a number of communication systems, wherein the first, thethird and the fourth communication systems are adapted to Time DivisionMultiple Access service, and the second communication system is adaptedto one of Code Division Multiple Access and Frequency Division MultipleAccess services.

The above structure has the switch unit for switching betweentransmission and reception modes for the communication systems of TimeDivision Multiple Access service, and the filter for branching andcombining transmission and reception signals for the communicationsystem of Code Division Multiple Access and Frequency Division MultipleAccess services. The invention can thus provide the antenna diplexer ofsmall size and high performance, yet adaptable to the multiple number ofcommunication systems that has been hitherto considered difficult toattain.

Furthermore, this invention covers a communication terminal featuringthe above high-frequency compound switch module connected with anantenna, a transmission circuit, and a reception circuit.

Adoption of the above structure provides the communication terminal withcapability of using a multiple number of communication systems. Inaddition, since the high-frequency compound switch module has a smallloss and small size, it can reduce amount of electric current duringtransmission and prevent a reception signal from being decreased,thereby providing the communication terminal with a prolongedoperational time for telephone communication and high receivingsensitivity beside the small size.

As has been obvious from the above, this invention can realize thehigh-frequency compound switch module of small size and high performancewith capability of adapting to the plurality of different communicationsystems.

INDUSTRIAL APPLICABILITY

The present invention relates to a high-frequency compound switch moduleadaptable for a mobile communication device such as a handy phone andthe like, and a communication terminal using the same. The inventionalso provides an antenna diplexer of small size, high performance, andadaptable to a number of different communication systems.

1. A high-frequency compound switch module adaptable for at least twodifferent communication systems, including a first communication systemand a second communication system, said first communication systemcomprising: a switch unit for switching connection of a signal from anantenna to any of a transmission circuit and a reception circuit of saidfirst communication system based on a signal from a control terminal; afilter provided on the reception circuit side, for filtering out a firstreception signal; and a first phase shift line provided between saidfilter and said switch unit, and said second communication systemcomprising: a second phase shift line provided between said switch unitand said first phase shift line; and a branching filter provided inseries to said second phase shift line for branching a signal from saidsecond phase shift line into a second transmission signal and a secondreception signal, wherein said switch module is capable of performing atleast a receiving process of said first communication system whileperforming transmission/reception with said second communication system.2. A high-frequency compound switch module adaptable for at least threedifferent communication systems, including a first communication system,a second communication system and a third communication system, saidswitch module having a switch unit for switching connection of a signalfrom an antenna to any of transmission circuits and reception circuitsof said first and said third communication systems based on a signalfrom a control terminal, said first communication system comprising: afirst filter provided on a first reception circuit side, for filteringout a first reception signal; and a first phase shift line providedbetween said first filter and said switch unit, said secondcommunication system comprising: a second phase shift line providedbetween said switch unit and said first phase shift line; and abranching filter provided in series to said second phase shift line forbranching a signal from said second phase shift line into a secondtransmission signal and a second reception signal, and said thirdcommunication system comprising: a terminal for connection of one end ofsaid switch unit to a third transmission circuit; and a third filter forfiltering out a third reception signal, wherein said switch unit alsoswitches a third transmission signal and a third reception signal, andsaid switch module is capable of performing at least a receiving processof said first communication system while performingtransmission/reception with said second communication system.
 3. Ahigh-frequency compound switch module adaptable for at least fourdifferent communication systems, including a first communication system,a second communication system, a third communication system and a fourthcommunication system, said switch module having a switch unit forswitching connection of a signal from an antenna to any of transmissioncircuits and reception circuits of said first through said fourthcommunication systems based on a signal from a control terminal, saidfirst communication system comprising: said switch unit for switchingconnection of the signal from said antenna to any of the transmissioncircuit and the reception circuit of said first communication system; afirst filter provided on a reception circuit side for filtering out afirst reception signal; and a first phase shift line provided betweensaid first filter and said switch unit, said second communication systemcomprising: a second phase shift line provided between said switch unitand said first phase shift line; and a branching filter provided inseries to said second phase shift line for branching a signal from saidsecond phase shift line into a second transmission signal and a secondreception signal, said third communication system comprising: a terminalfor connection of one end of said switch unit to a third transmissioncircuit; and a third filter for filtering out a third reception signal,and said fourth communication system comprising: a terminal forconnection to said third transmission circuit; and a fourth filter forfiltering out a fourth reception signal, wherein said switch module iscapable of performing at least a receiving process of said firstcommunication system while performing transmission/reception with saidsecond communication system.
 4. A high-frequency compound switch moduleadaptable for at least two different communication systems, including afirst communication system and a second communication system, saidswitch module having a diplexer for branching a signal from an antennaand also combining transmission signals and reception signals of saidfirst communication system and said second communication system, saidfirst communication system comprising a switch unit for switchingconnection of a signal from said diplexer to one of a transmissioncircuit and a reception circuit of said first communication system basedon a signal from a control terminal, and said second communicationsystem comprising a branching filter for branching another signal fromsaid diplexer into a second transmission signal and a second receptionsignal, wherein said switch module is capable of performing at least areceiving process of said first communication system while performingtransmission/reception with said second communication system.
 5. Ahigh-frequency compound switch module adaptable for at least threedifferent communication systems, including a first communication system,a second communication system and a third communication systems, saidswitch module having: a first switch unit for switching connection of asignal from an antenna to any of transmission circuits and receptioncircuits of said first and said third communication systems based on asignal from a control terminal; and a diplexer connected to said firstswitch unit for combining and branching transmission signals andreception signals of said first communication system and said secondcommunication system, said first communication system comprising asecond switch unit for switching connection of a signal from saiddiplexer to one of a transmission circuit and a reception circuit ofsaid first communication system based on a signal from the controlterminal, said second communication system comprising a branching filterfor branching another signal from said diplexer into a secondtransmission signal and a second reception signal, and said thirdcommunication system comprising: a terminal for connection of one end ofsaid first switch unit to a third transmission circuit; and anotherterminal for connection of another end of said first switch unit to athird reception circuit, wherein said first switch unit also switches athird transmission signal and a third reception signal, and said switchmodule is capable of performing at least a receiving process of saidfirst communication system while performing transmission/reception withsaid second communication system.
 6. A high-frequency compound switchmodule adaptable for at least four different communication systems,including a first communication system, a second communication system, athird communication system and a fourth communication system, saidswitch module having: a first switch unit for switching connection of asignal from an antenna to any of transmission circuits and receptioncircuits of said first and said fourth communication systems based on asignal from a control terminal; and a diplexer connected to said firstswitch unit for combining and branching transmission signals andreception signals of said first communication system and said secondcommunication system, said first communication system comprising asecond switch unit for switching connection of a signal from saiddiplexer to one of a transmission circuit and a reception circuit ofsaid first communication system based on a signal from the controlterminal, said second communication system comprising a branching filterfor branching another signal from said diplexer into a secondtransmission signal and a second reception signal, said thirdcommunication system comprising: a terminal for connection of one end ofsaid first switch unit to a third transmission circuit; and anotherterminal for connection of another end of said first switch unit to athird reception circuit, and said fourth communication systemcomprising: a terminal for connection of still another end of said firstswitch unit to a fourth transmission circuit; and another terminal forconnection of yet another end of said first switch unit to a fourthreception circuit, wherein said first switch unit also switches any ofthird and fourth transmission signals and third and fourth receptionsignals, and said switch module is capable of performing at least areceiving process of said first communication system while performingtransmission/reception with said second communication system.
 7. Ahigh-frequency compound switch module adaptable for at least threedifferent communication systems, including a first communication system,a second communication system and a third communication system, saidswitch module having a first switch unit for switching connection of asignal from an antenna to any of transmission circuits and receptioncircuits of said first and said third communication systems based on asignal from a control terminal, said first communication systemcomprising: said first switch unit for also switching connection of asignal from the antenna to any of the transmission circuit and thereception circuit of said first communication system; a first filterprovided on the reception circuit side, for filtering out a firstreception signal; and a first phase shift line provided between saidfirst filter and said first switch unit, said third communication systemcomprising: a terminal for connection of one end of said first switchunit to a third transmission circuit; and a third filter for filteringout a third reception signal, and said second communication systemcomprising: a second switch unit connected between said first switchunit and said antenna, for switching the signal from said antenna to anyof a transmission circuit and a reception circuit of said secondcommunication system based on a signal from the control terminal; asecond phase shift line connected in series to said second switch unit;and a second branching filter connected in series to said second phaseshift line for branching a second transmission signal and a secondreception signal, wherein said switch module is capable of performing atleast a receiving process of said first communication system whileperforming transmission/reception with said second communication system.8. A high-frequency compound switch module adaptable for at least fourdifferent communication systems, including a first communication system,a second communication system, a third communication system and a fourthcommunication system, said switch module having a first switch unit forswitching connection of a signal from an antenna to any of transmissioncircuits and reception circuits of said first, said third and saidfourth communication systems based on a signal from a control terminal,said first communication system comprising: said first switch unit forswitching connection of the signal from the antenna to any of thetransmission circuit and the reception circuit of said firstcommunication system; a first filter provided on a reception circuitside for filtering out a first reception signal; and a first phase shiftline provided between said first filter and said first switch unit, saidthird communication system comprising: a terminal for connection of oneend of said first switch unit to a third transmission circuit; and athird filter for filtering out a third reception signal, said fourthcommunication system comprising: switching between a fourth transmissionsignal and a fourth reception signal with said first switch unit; aterminal for connection of another end of said first switch unit to afourth transmission circuit; and a fourth filter for filtering out thefourth reception signal, and said second communication systemcomprising: a second switch unit connected between said first switchunit and said antenna, for switching the signal from said antenna to anyof a transmission circuit and a reception circuit of said secondcommunication system based on a signal from the control terminal; asecond phase shift line connected in series to said second switch unit;and a second branching filter connected in series to said second phaseshift line for branching a second transmission signal and a secondreception signal, wherein said switch module is capable of performing atleast a receiving process of said first communication system whileperforming transmission/reception with said second communication system.9. A high-frequency compound switch module adaptable for at least threedifferent communication systems, including a first communication system,a second communication system and a third communication system, saidswitch module having a diplexer for splitting a signal from an antenna,said first communication system comprising: a first switch unit forswitching connection of a signal from said diplexer to one of atransmission circuit and a reception circuit of said first communicationsystem based on a signal from a control terminal; a first filterprovided on the reception circuit side, for filtering out a firstreception signal; and a first phase shift line provided between saidfirst filter and said first switch unit, said third communication systemcomprising: a second switch unit for switching connection of anothersignal from said diplexer to one of a transmission circuit and areception circuit of said third communication system based on a signalfrom the control terminal; a second filter provided on the receptioncircuit side, for filtering out a third reception signal; and atransmission terminal connected to a third transmission circuit, andsaid second communication system comprising: said second switch unit forswitching the signal from said antenna to any of a transmission circuitand a reception circuit of said second communication system based on asignal from the control terminal; a second phase shift line connected inseries to said second switch unit; and a second branching filterconnected in series to said second phase shift line for branching asecond transmission signal and a second reception signal, wherein saidswitch module is capable of performing at least a receiving process ofsaid first communication system while performing transmission/receptionwith said second communication system.
 10. The high-frequency compoundswitch module according to one of claim 1 through claim 3, wherein saidswitch module has: an impedance value equivalent to an open circuit in afrequency of said first communication system when measured at a point ofconnection between said first phase shift line and said second phaseshift line toward transmission and reception circuits of said secondcommunication system; and another impedance value equivalent to an opencircuit in a frequency of said second communication system when measuredat the same point of connection toward the transmission and thereception circuits of said first communication system.
 11. Thehigh-frequency compound switch module according to one of claim 4 andclaim 5, wherein said switch module has: an impedance value equivalentto an open circuit in a frequency of said first communication systemwhen measured from an antenna terminal toward transmission and receptioncircuits of said second communication system; and another impedancevalue equivalent to an open circuit in a frequency of said secondcommunication system when measured from the antenna terminal toward thetransmission and the reception circuits of said first communicationsystem.
 12. The high-frequency compound switch module according to oneof claim 1 through claim 9, further comprising a low pass filterconnected to each of circuits between said switch unit and transmissionterminals of said communication systems.
 13. The high-frequency compoundswitch module according to one of claim 1 through claim 9, wherein saidbranching filter in said second communication system comprises SAWfilters disposed to both transmission and reception lines, and a thirdphase shift line for impedance matching connected between said SAWfilters in said transmission and reception lines.
 14. The high-frequencycompound switch module according to one of claim 1 through claim 9,wherein said branching filter in said second communication systemcomprises a filter composed of a multilayer structure of dielectricmaterial disposed to one of transmission and reception lines, and an SAWfilter disposed to the other of said lines.
 15. The high-frequencycompound switch module according to one of claim 1 through claim 9,wherein said branching filter in said second communication systemcomprises filters composed of multilayer structure of dielectricmaterial disposed to both transmission and reception lines.
 16. Thehigh-frequency compound switch module according to one of claim 1through claim 9, wherein said branching filter in said secondcommunication system comprises acoustic wave filters using bulk wave,disposed to both transmission and reception lines.
 17. Thehigh-frequency compound switch module according to one of claim 1through claim 3, wherein said first phase shift line and said secondphase shift line comprise any of a π-type network and T-type networkhaving a line-to-ground capacitor and a series inductor, and a π-typenetwork and T-type network having a line-to-ground inductor and a seriescapacitor.
 18. The high-frequency compound switch module according toone of claim 1 through claim 9, wherein a circuit structure of saidswitch module comprises any of an electrode pattern formed on top of adielectric material layer provided above a grounding pattern and anotherelectrode pattern formed on a grounding pattern with a spacing ofdielectric material therebetween.
 19. The high-frequency compound switchmodule according to one of claim 1 through claim 3, wherein at leastsaid first phase shift line and said second phase shift lineconstituting a circuit of said switch module comprise an electrodepattern formed inside a multilayer structure of dielectric material. 20.The high-frequency compound switch module according to one of claim 1through claim 9, wherein said switch unit and said filter are mounted ona multilayer substrate.
 21. The high-frequency compound switch moduleaccording to one of claims 2, 3 and 5, wherein at least one of saidfirst communication system, or said third communication system operatefor Time Division Multiple Access service, and said second communicationsystem operates for any of Code Division Multiple Access and FrequencyDivision Multiple Access services.
 22. The high-frequency compoundswitch module according to one of claims 3 and 6, wherein at least oneof said first communication system, said third communication system orsaid fourth communication system operate for Time Division MultipleAccess service, and said second communication system operates for any ofCode Division Multiple Access and Frequency Division Multiple Accessservices.
 23. A communication terminal comprising an antenna, atransmission circuit and a reception circuit connected to ahigh-frequency compound switch module recited in one of claim 1 throughclaim
 9. 24. A high-frequency compound switch module adaptable for atleast two different communication systems, including a firstcommunication system and a second communication system, said firstcommunication system comprising: a switch unit for switching connectionof a signal from an antenna to any of a transmission circuit and areception circuit of said first communication system based on a signalfrom a control terminal; said second communication system comprising: asecond phase shift line provided between said switch unit and a firstphase shift line; wherein said switch module is capable of performing atleast a receiving process of said first communication system whileperforming transmission/reception with said second communication system,said high-frequency compound switch module further comprising a diplexerconnected between said switch unit and a reception terminal of saidfirst communication system and transmission and reception terminals ofsaid second communication system, for combining and branching thereception signal of said first communication system and the transmissionsignal and the reception signal of said second communication system. 25.A high-frequency compound switch module adaptable for at least threedifferent communication systems, including a first communication system,a second communication system and a third communication system, saidfirst communication system comprising: said switch module having aswitch unit for switching connection of a signal from an antenna to anyof transmission circuits and reception circuits of said first and saidthird communication systems based on a signal from a control terminal,said second communication system comprising: a second phase shift lineprovided between said switch unit and a first phase shift line; and saidthird communication system comprising: a terminal for connection of oneend of said switch unit to a third transmission circuit; and a thirdfilter for filtering out a third reception signal, wherein said switchunit also switches a third transmission signal and a third receptionsignal, and said switch module is capable of performing at least areceiving process of said first communication system while performingtransmission/reception with said second communication system, saidhigh-frequency compound switch module further comprising a diplexerconnected between said switch unit and a reception terminal of saidfirst communication system and transmission and reception terminals ofsaid second communication system, for combining and branching thereception signal of said first communication system and the transmissionsignal and the reception signal of said second communication system. 26.A high-frequency compound switch module adaptable for at least fourdifferent communication systems, including a first communication system,a second communication system, a third communication system and a fourthcommunication system, said switch module having a switch unit forswitching connection of a signal from an antenna to any of transmissioncircuits and reception circuits of said first through said fourthcommunication systems based on a signal from a control terminal, saidfirst communication system comprising: said switch unit for switchingconnection of the signal from said antenna to any of the transmissioncircuit and the reception circuit of said first communication system;said second communication system comprising: a second phase shift lineprovided between said switch unit and a first phase shift line; and saidthird communication system comprising: a terminal for connection of oneend of said switch unit to a third transmission circuit; and a thirdfilter for filtering out a third reception signal, and said fourthcommunication system comprising: a terminal for connection to said thirdtransmission circuit; and a fourth filter for filtering out a fourthreception signal, wherein said switch module is capable of performing atleast a receiving process of said first communication system whileperforming transmission/reception with said second communication system,said high-frequency compound switch module further comprising a diplexerconnected between said switch unit and a reception terminal of saidfirst communication system and transmission and reception terminals ofsaid second communication system, for combining and branching thereception signal of said first communication system and the transmissionsignal and the reception signal of said second communication system.